1. Field of the Invention
This invention relates generally to fluid spray apparatus, particularly to irrigation devices, and more particularly to an improved fluid spray head for sprinkler apparatus.
2. Description of the Prior Art
A wide variety of irrigation apparatus and sprinklers have been devised to provide proper irrigation to lawns and other vegetation. Irrigation sprinklers may be generally classified as either fixed discharge or moving discharge sprinklers.
A moving discharge sprinkler is characterized by a movable spray head which directs one or more water streams outwardly from the head of the sprinkler in a predetermined direction in cyclic or oscillatory pattern to sweep over the area to be irrigated. Moving discharge sprinklers have the advantage of low precipitation rates, which allows them to distribute a relatively small flow of water over a relatively large area. However, such moving sprinklers tend to be complex in construction, costly to manufacture, subject to wear and malfunction, and sensitive to water flow rates and pressures. The coverage of these sprinklers is adversely effective by the wind and they are ill-suited to small and/or non-circular shaped areas. They are generally incapable of adequate trimming, that is, spraying along, but not appreciably beyond the border of an irrigation area. In view of their necessity to rotate or oscillate, a relatively large area of movement is required. Accordingly, moving sprinklers are not satisfactory for all uses.
Typical fixed discharge sprinkler systems normally have a stationary spray head which directs a number of discrete diverging streams of water or a generally continuous fan-shaped spray of water spreading outwardly from the spray head over a predetermined angular sector. Fixed discharge sprinklers have the advantages of maximum simplicity, low cost, reliability, immunity to wear, and the ability to irrigate small or non-circular shaped areas, and to adequately trim the borders of such areas. The chief disadvantage of fixed discharge sprinklers is that they continuously deliver a relatively large flow of water to a relatively small area and thus produce relatively high precipitation rates over the area.
The problem of the characteristicly inflexible operation of fixed discharge sprinklers is further compounded by the fact that they are usually operated in groups from a common control valve. These control valves are usually controlled or operated by a single manual or automatic controller which causes all of the sprinklers to deliver approximately the same amount of water to the areas surrounding the respective sprinklers. Thus, some areas which require less water are over watered, while areas requiring more water are under watered.
Various prior art devices have attempted to eliminate the disadvantages of selective flow control and precipitation rates in fixed discharge irrigation sprinkler systems. U.S. Pat. No. 3,454,225 and No. 3,940,066 issued to E. J. Hunter disclose means for controlling the precipitation rate from a fluid spray head and a specific means for adjusting the fluid flow rate of a spray head in a pop-up sprinkler by rotating the tubular riser. U.S. Pat. No. 3,454,225 provides a means for adjusting the precipitation rate with a spray head which telescopes in and out of the main tubular body to thereby decrease or increase the effective size of the orifices.
However, a problem with sprinkler systems having a spray head which is telescopingly adjustable within the main tubular body is that the engagement between the tubular portion of the spray head and main tubular body is not fluid tight and that after much use, or during conditions of high fluid pressure, leaking results.
Another problem with fixed discharge sprinkler systems is that they have been limited in the shape or pattern of area which they can cover. In prior spray heads, the shape of the irrigated areas has been determined by the placement of or lack of orifices positioned around the spray head. However, this method of spray head design is very limited in the shape or pattern of areas it can spray.
However, while some of the above problems have been eliminated in some appratus by specific constructions, it has nevertheless been desirable to have a sprinkler apparatus having the combined ability to adjust the flow rate, the precipitation rate, and to provide for the uniform fluid coverage of any desired shape, and having this combined ability in a simple, single adjustment means.
Accordingly, the principal object of this invention is to provide a sprinkler apparatus having a fixed discharge fluid spray head capable of adjusting the fluid flow rate, the precipitation rate, and to provide uniform fluid coverage for any desired shape area.
Another object is to provide a fluid spray head which can adjust the flow of water into the spray head of a sprinkler system.
Yet another object is to provide a sprinkler system having a telescopingly adjustable spray head within a tubular main body wherein the problem of leaking through the sliding engagement is eliminated.
A still further object of this invention is to provide a method of constructing a fluid spray head which is adapted to spray a preselected shaped ground area.
Yet another object is to provide a method of spraying a preselected shaped ground area.